Method for producing fluorocarbon refrigerant, method for storing fluorocarbon refrigerant, method for producing heat pump device, and carbon dioxide storage system

Abstract

The method for producing a fluorocarbon refrigerant includes a step of recovering carbon dioxide using an adsorbent, and a step of synthesizing a fluorocarbon refrigerant using the recovered carbon dioxide as a raw material.

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a fluorocarbon refrigerant, a method for storing a fluorocarbon refrigerant, a method for producing a heat pump device, and a carbon dioxide storage system. [Background technology]

[0002] Patent Document 1 discloses a direct air capture (DAC) technology that captures carbon dioxide from factory exhaust or the air around a factory. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 230045 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, from the perspective of preventing global warming, carbon dioxide fixation technology that prevents the carbon dioxide captured by the above technology from being released into the atmosphere is also being researched. However, if the captured carbon dioxide is prevented from being released into the atmosphere by storing it in underground facilities or tanks, it may require a huge amount of labor and energy to manage them.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a method for producing a fluorocarbon refrigerant, a method for storing a fluorocarbon refrigerant, a method for producing a heat pump device, and a carbon dioxide storage system that can reduce the effort and energy required to store and manage recovered carbon dioxide. [Means for solving the problem]

[0006] One embodiment of a method for producing a fluorocarbon refrigerant in the present disclosure includes a step of recovering carbon dioxide using an adsorbent, and a step of synthesizing a fluorocarbon refrigerant using the recovered carbon dioxide as a raw material. Effect of the Invention

[0007] According to one aspect of the present disclosure, carbon dioxide can be captured from a gas to be treated, such as the atmosphere, indoor air, or factory exhaust, using an adsorbent, and a fluorocarbon refrigerant can be synthesized using the captured carbon dioxide as a raw material. The fluorocarbon refrigerant is chemically stable, and by using it as a heat medium in a heat pump device, for example, the synthesized fluorocarbon refrigerant can be stably stored in the heat pump device from the manufacture to the disposal of the heat pump device. In other words, since there is no need to separately prepare underground facilities, tanks, etc. for storing the captured carbon dioxide, the effort and energy required for storing and managing the captured carbon dioxide can be reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a carbon dioxide storage system according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a carbon dioxide capture device included in the carbon dioxide storage system according to the embodiment. [Diagram 3] FIG. 2 is a schematic diagram of a carbon recycling fluorocarbon refrigerant synthesis device included in the carbon dioxide storage system according to the embodiment. [Figure 4] 1 is a schematic diagram of a heat pump device included in a carbon dioxide storage system according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiments, and can be arbitrarily modified within the scope of the appended claims.

[0010] FIG. 1 is a schematic diagram of a carbon dioxide storage system 1 according to the present embodiment. As shown in Fig. 1, the carbon dioxide storage system 1 is a system that captures and stores carbon dioxide (CO2) from gas to be treated, such as the atmosphere, indoor air, or factory exhaust. The carbon dioxide storage system 1 includes a carbon dioxide capture device 50 that captures carbon dioxide from the gas to be treated, a carbon recycling fluorocarbon refrigerant synthesis device 60 that synthesizes a fluorocarbon refrigerant from the captured carbon dioxide, and a heat pump device 70 that uses the synthesized fluorocarbon refrigerant as a heat medium.

[0011] FIG. 2 is a schematic diagram of a carbon dioxide capture device 50 in this embodiment. As shown in FIG. 2, the carbon dioxide capture device 50 includes a first supply path 2, a carbon dioxide adsorption section 3, a first outlet path 4, a regenerating fluid supply section 5, a second supply path 6, a heater 7, a pressure reducer 8, a second outlet path 9, a carbon dioxide separator 10, a compressor 11, and a cooler 12.

[0012] The first supply path 2 is connected to an adsorption region 31 of the carbon dioxide adsorption section 3, which will be described later. The first supply path 2 guides a gas to be treated, such as the atmosphere, room air, or factory exhaust air, to the adsorption region 31 of the carbon dioxide adsorption section 3. The first supply path 2 is provided with a blower 21 for sending the gas to be treated to the carbon dioxide adsorption section 3. If the gas to be treated introduced into the first supply path 2 can flow to the carbon dioxide adsorption section 3 without using the blower 21, the blower 21 need not be provided. If the gas to be treated is factory exhaust air or the like, the first supply path 2 may be provided with an exhaust gas treatment device for removing nitrogen oxides, soot, and the like in advance from the gas to be treated.

[0013] The carbon dioxide adsorption section 3 includes a first region 3A and a second region 3B. The first region 3A and the second region 3B each include an adsorbent capable of adsorbing carbon dioxide and a container for accommodating the adsorbent. The container of the first region 3A and the container of the second region 3B are configured to be mutually exchangeable. The carbon dioxide adsorption section 3 also includes an adsorption region 31 for adsorbing carbon dioxide contained in the gas to be treated, and a regeneration region 32 for regenerating the adsorbent to which carbon dioxide has been adsorbed. In this embodiment, "regeneration" refers to desorbing carbon dioxide from the adsorbent to which carbon dioxide has been adsorbed, and returning the adsorbent to a state capable of adsorbing carbon dioxide again. In the example shown in FIG. 2, the first region 3A is the adsorption region 31, and the second region 3B is the regeneration region 32.

[0014] Examples of the adsorbent include amine, silica gel, zeolite, activated carbon, diatomaceous earth, and alumina. Carbon dioxide contained in the gas to be treated can be separated from other components of the gas to be treated by adsorbing the carbon dioxide to the adsorbent. The adsorbent may be in a granular or powdered form. The granular form may be, for example, a bead (spherical) or pellet (cylindrical) form. When a powdered adsorbent is used, the adsorbent may be supported on the surface of a substrate. The substrate may be in a honeycomb shape.

[0015] In the adsorption region 31, at least a portion of the carbon dioxide contained in the gas to be treated is adsorbed by the adsorbent and removed, so that a gas having a lower concentration of carbon dioxide than the gas to be treated is obtained.

[0016] The regeneration region 32 regenerates the adsorbent that has adsorbed carbon dioxide in the adsorption region 31, using a regenerating fluid F1 supplied by a regenerating fluid supply unit 5. The regeneration region 32 has a function of desorbing carbon dioxide from the adsorbent. The regeneration region 32 includes a heating device, such as a heater, for heating the adsorbent. The heating device heats the adsorbent in the presence of the regenerating fluid F1, thereby desorbing carbon dioxide from the adsorbent. The adsorbent is regenerated by the desorption of carbon dioxide. The regenerating fluid F1 containing the carbon dioxide desorbed from the adsorbent is discharged from the regeneration region 32 as a regeneration discharge fluid F2.

[0017] The regeneration zone 32 may include a pressure reducing device, such as a vacuum pump, that subjects the adsorbent to reduced pressure to facilitate desorption of carbon dioxide from the adsorbent.

[0018] The first outlet path 4 is connected to the adsorption region 31. Gas with a reduced carbon dioxide concentration obtained by passing the gas to be treated through the adsorption region 31 is introduced into the first outlet path 4. The first outlet path 4 releases the gas with a reduced carbon dioxide concentration by the adsorption region 31 into the atmosphere, a living space, or the like. When the gas to be treated is factory exhaust gas, for example, the first outlet path 4 may be provided with an exhaust gas treatment device.

[0019] The regenerating fluid supply unit 5 is a supply source of the regenerating fluid F1, and supplies the regenerating fluid F1 toward the regenerating region 32 of the carbon dioxide adsorption unit 3. The regenerating fluid supply unit 5 may include a tank for storing the regenerating fluid F1, a discharge pump for sending the regenerating fluid F1 toward the regenerating region 32, and the like. Examples of the regenerating fluid F1 include nitrogen (N2), hydrogen (H2), and methane (CH4). The regenerating fluid F1 in this embodiment is a gas, but may also be a liquid.

[0020] The second supply path 6 is connected to the regenerating fluid supply unit 5 and the regenerating region 32 of the carbon dioxide adsorption unit 3. The second supply path 6 guides the regenerating fluid F1 supplied from the regenerating fluid supply unit 5 to the regenerating region 32.

[0021] The heater 7 and the pressure reducer 8 are provided in the second supply path 6. The pressure reducer 8 is provided downstream of the heater 7, that is, between the heater 7 and the regeneration area 32. The heater 7 is, for example, a heat exchanger or a heater, and can heat the regeneration fluid F1 to a temperature suitable for desorption of carbon dioxide from the adsorbent in the regeneration area 32. The heater 7 can heat the regeneration fluid F1 so that the temperature of the regeneration fluid F1 in the regeneration area 32 is 90°C to 120°C. The pressure reducer 8 is, for example, a pressure reducing valve, and reduces the pressure of the regeneration fluid F1 to a pressure suitable for desorption of carbon dioxide from the adsorbent in the regeneration area 32. The heater 7 and the pressure reducer 8 are not essential elements in this embodiment, and one or both of them may not be provided in the second supply path 6.

[0022] The second outlet path 9 is connected to the regeneration region 32 of the carbon dioxide adsorption section 3 and the carbon dioxide separator 10. The second outlet path 9 leads the regeneration discharge fluid F2 discharged from the regeneration region 32 to the carbon dioxide separator 10.

[0023] The carbon dioxide separator 10 separates at least a portion of the carbon dioxide contained in the regeneration discharge fluid F2 using a separation method such as liquefaction separation, membrane separation, adsorption separation, etc. The carbon dioxide separator 10 may employ one of these separation methods or a combination of two or more of them.

[0024] The carbon dioxide separator 10 using liquefaction separation liquefies, for example, a specific component and separates it from other components (gases) in the regeneration exhaust fluid F2. Specifically, for example, carbon dioxide is liquefied under high pressure and low temperature conditions and separated from other components (gases).

[0025] The carbon dioxide separator 10 using membrane separation separates a specific component from other components, for example, by using a separation membrane that allows components with small molecular sizes to permeate. Specifically, for example, a separation membrane that selectively allows carbon dioxide to permeate is used. This separation membrane separates carbon dioxide from a mixed fluid (i.e., regeneration discharge fluid F2) that contains carbon dioxide and other components (nitrogen, hydrogen, methane, etc.). Examples of separation membranes include organic membranes (such as dendrimer membranes) and inorganic membranes (such as zeolite membranes, silica membranes, carbon membranes, etc.).

[0026] The carbon dioxide separator 10 using adsorption separation separates specific components by, for example, adsorbing them onto an adsorbent. Examples of the adsorbent include amines, silica gel, zeolite, activated carbon, diatomaceous earth, and alumina. Specifically, for example, carbon dioxide can be separated from other components in the regeneration discharge fluid F2 by adsorbing it onto the adsorbent.

[0027] The carbon dioxide separated from the regeneration discharge fluid F2 by the carbon dioxide separator 10 is supplied to the carbon recycle fluorocarbon refrigerant synthesis device 60. The regeneration discharge fluid F2, in which the concentration of carbon dioxide has been reduced by the separation of carbon dioxide, is discharged as discharge fluid F3 from the carbon dioxide separator 10. The discharge fluid F3 may be supplied to the regeneration fluid supply unit 5 and used again as the regeneration fluid F1.

[0028] The compressor 11 and the cooler 12 are provided in the second outlet path 9. The cooler 12 is provided downstream of the compressor 11, that is, between the compressor 11 and the carbon dioxide separator 10. The compressor 11 can increase the pressure of the regeneration discharge fluid F2 to a pressure suitable for separation of carbon dioxide from the regeneration discharge fluid F2 in the carbon dioxide separator 10. The cooler 12 is, for example, a heat exchanger, and can reduce the temperature of the regeneration discharge fluid F2, which has been pressurized by the compressor 11, to a temperature suitable for separation of carbon dioxide from the regeneration discharge fluid F2 in the carbon dioxide separator 10. Note that the compressor 11 and the cooler 12 are not essential elements in this embodiment, and one or both of them may not be provided in the second outlet path 9.

[0029] At least one of the devices included in the carbon dioxide capture device 50 may be driven by renewable energy such as sunlight, wind power, hydroelectric power, geothermal power, solar heat, atmospheric heat, or other heat present in nature. In other words, the carbon dioxide capture device 50 may be configured to capture carbon dioxide using renewable energy.

[0030] FIG. 3 is a schematic diagram of a carbon recycling fluorocarbon refrigerant synthesis unit 60 according to this embodiment. As shown in FIG. 3, the carbon recycling fluorocarbon refrigerant synthesis unit 60 includes a hydrocarbon synthesis unit 15 that synthesizes hydrocarbons from carbon dioxide (CO2) and hydrogen (H2) recovered in the carbon dioxide recovery unit 50, a dichloromethane synthesis unit 16 that synthesizes dichloromethane (CH2Cl2) by a radical reaction between the hydrocarbon and chlorine (Cl2), and a fluorocarbon refrigerant synthesis unit 17 that reacts the dichloromethane with hydrogen fluoride (HF) to synthesize difluoromethane (CH2F2, refrigerant number: R32), which is a fluorocarbon refrigerant.

[0031] The hydrocarbon synthesis unit 15 includes a catalyst that promotes a synthesis reaction from carbon dioxide and hydrogen to hydrocarbons, and a reaction chamber (reactor) that houses the catalyst and receives the carbon dioxide and hydrogen captured by the carbon dioxide capture unit 50. The hydrocarbon synthesized in the hydrocarbon synthesis unit 15 is, for example, methane (CH4). Examples of the catalyst in the hydrocarbon synthesis unit 15 include solid catalysts using inorganic materials and biocatalysts using bacteria. In order to keep such catalysts at a temperature suitable for the synthesis of hydrocarbons, the hydrocarbon synthesis unit 15 may be provided with a heating device such as a heater or a cooling device using a heat exchanger. The hydrocarbons synthesized in the hydrocarbon synthesis unit 15 are supplied to the dichloromethane synthesis unit 16.

[0032] The hydrogen supplied to the hydrocarbon synthesis section 15 may be produced by any method, but may be produced by electrolysis of water, and renewable energy may be used for this electrolysis.

[0033] The dichloromethane synthesis unit 16 includes a reaction chamber (reactor) into which the hydrocarbon (methane) synthesized in the hydrocarbon synthesis unit 15 and chlorine (Cl2) are introduced, and a heating device such as a heater for heating the inside of the reaction chamber. The chlorine supplied to the dichloromethane synthesis unit 16 may be generated by any method. The heating device of the dichloromethane synthesis unit 16 raises the temperature inside the reaction chamber to a temperature suitable for causing a radical reaction between the hydrocarbon (methane) and chlorine, for example, to 400°C to 500°C. Dichloromethane (CH2Cl2) is synthesized by the radical reaction between the hydrocarbon and chlorine in the reaction chamber. The synthesized dichloromethane is supplied to the fluorocarbon refrigerant synthesis unit 17. Renewable energy may be used to operate the heating device.

[0034] In addition to the heating device of the dichloromethane synthesis section 16, or instead of this heating device, a photocatalyst that promotes a radical reaction between hydrocarbons and chlorine by irradiation with light may be provided in the reaction chamber.

[0035] The fluorocarbon refrigerant synthesis unit 17 includes a fluorination catalyst that promotes a synthesis reaction from dichloromethane and hydrogen fluoride (HF) to difluoromethane (CH2F2), and a reaction chamber (reactor) that contains the fluorination catalyst and is supplied with the dichloromethane and hydrogen fluoride synthesized in the dichloromethane synthesis unit 16. The hydrogen fluoride supplied to the fluorocarbon refrigerant synthesis unit 17 may be produced by any method. As an example of the fluorination catalyst, there may be mentioned a catalyst having a catalyst component mainly composed of chromium oxide and optionally further containing at least one element selected from the group consisting of In, Zn, Ni, Co, Mg and Al, and a carrier that supports the catalyst component, and at least a part of the catalyst component is fluorinated with hydrogen fluoride. The carrier may be, for example, activated alumina having fine pores.

[0036] In order to bring the fluorination catalyst in fluorocarbon refrigerant synthesis unit 17 to a temperature suitable for the synthesis of difluoromethane, a heating device such as a heater or a cooling device using a heat exchanger, etc. may be provided in fluorocarbon refrigerant synthesis unit 17. Difluoromethane synthesized in fluorocarbon refrigerant synthesis unit 17 is supplied to heat pump device 70 directly or via a cylinder, etc.

[0037] The fluorocarbon refrigerant synthesized in the carbon recycle fluorocarbon refrigerant synthesis unit 60 is a hydrofluorocarbon (HFC) made from the carbon dioxide recovered in the carbon dioxide recovery unit 50, and does not contain chlorine.

[0038] The carbon recycling fluorocarbon refrigerant synthesis apparatus 60 may further include a mixed refrigerant production section (not shown) that produces a mixed refrigerant containing, as one of its components, the difluoromethane synthesized in the fluorocarbon refrigerant synthesis section 17. Such a mixed refrigerant production section includes a mixer, and the difluoromethane synthesized in the fluorocarbon refrigerant synthesis section 17 and another refrigerant supplied from outside the carbon recycling fluorocarbon refrigerant synthesis apparatus 60 are supplied to the mixer and mixed together to produce a mixed refrigerant.

[0039] The other refrigerant supplied from outside the carbon recycle fluorocarbon refrigerant synthesis unit 60 to the mixed refrigerant production unit may be not only a newly produced refrigerant but also a refrigerant recovered from an existing heat pump device. Examples of the other refrigerant include fluorocarbon refrigerants and olefin-based refrigerants (hydrofluoroolefins, HFOs). Examples of the other fluorocarbon refrigerants supplied from outside the carbon recycle fluorocarbon refrigerant synthesis unit 60 include hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs), and examples of the hydrochlorofluorocarbons include chlorodifluoromethane (CHClF2, refrigerant number: R22). By supplying chlorodifluoromethane to the mixed refrigerant production unit, a mixed refrigerant of the chlorodifluoromethane and difluoromethane synthesized in the fluorocarbon refrigerant synthesis unit 17 can be produced.

[0040] Examples of the olefin-based refrigerant supplied to the mixed refrigerant production section include HFO-1123, HFO-1224yd, HFO-1234yf, HFO-1234ze, R1233zd (HFO-1233zd), HFO-1226mzz(Z), HFO-1336mzz-Z, HFO-1336mzz-E, etc. By supplying an olefin-based refrigerant to the mixed refrigerant production section, a mixed refrigerant of the olefin-based refrigerant and difluoromethane synthesized in the fluorocarbon refrigerant synthesis section 17 can be produced.

[0041] FIG. 4 is a schematic diagram of a heat pump device 70 according to the present embodiment. 4, the heat pump device 70 includes a gas-to-liquefaction heat pump 80 and a recovery port 86. The heat pump 80 includes a heater 81, an expander 82, a cooler 83, a compressor 84, and a circulation path 85. The circulation path 85 is filled with a refrigerant F4 so as to be circulated.

[0042] The heater 81 is a heat exchanger that exchanges heat between the refrigerant F4 and a fluid F5 flowing outside the heat pump device 70. That is, the heater 81 heats the fluid F5 by heat exchange between the refrigerant F4 whose temperature has been increased by compression and the fluid F5. The fluid F5 may be either a gas or a liquid. The expander 82, for example an expansion valve, reduces the pressure of the refrigerant F4, thereby reducing the temperature of the refrigerant F4.

[0043] The cooler 83 is a heat exchanger that exchanges heat between the refrigerant F4 and the fluid F6 flowing outside the heat pump device 70. That is, the cooler 83 cools the fluid F6 by exchanging heat between the refrigerant F4, the temperature of which has been reduced by the pressure drop in the expander 82, and the fluid F6. The fluid F6 may be either a gas or a liquid. The compressor 84 compresses the refrigerant F4 to increase its pressure, thereby increasing the temperature of the refrigerant F4.

[0044] Circulation path 85 is a looped path, and connects heater 81, expander 82, cooler 83, and compressor 84 in this order. Circulation path 85 is filled with and stored as refrigerant F4, fluorocarbon refrigerant (e.g., difluoromethane synthesized in fluorocarbon refrigerant synthesis section 17) produced in carbon recycling fluorocarbon refrigerant synthesis device 60. Refrigerant F4 may be a mixed refrigerant. Refrigerant F4 circulates so as to pass through heater 81, expander 82, cooler 83, and compressor 84 in this order.

[0045] The recovery port 86 is connected to the circulation path 85. The refrigerant F4 filled in the circulation path 85 can be recovered via the recovery port 86. For example, when the heat pump device 70 has reached the end of its service life and is to be discarded, the refrigerant F4 is recovered via the recovery port 86. The recovered refrigerant F4 may be supplied to the mixed refrigerant production section of the carbon recycled fluorocarbon refrigerant synthesis device 60, for example, to produce a new refrigerant (e.g., a mixed refrigerant). The recovery port 86 may also be used as a filling port for filling the circulation path 85 with the refrigerant F4.

[0046] The heat pump device 70 may constitute, for example, an air conditioner. The air conditioner performs at least one of cooling and heating by utilizing heat absorption or release of the refrigerant F4. When heating the room, the indoor unit functions as a heater 81, and the outdoor unit functions as a cooler 83. When cooling the room, the indoor unit functions as a cooler 83, and the outdoor unit functions as a heater 81.

[0047] The heat pump device 70 may constitute, for example, a refrigerator-freezer device. The refrigerator-freezer device cools the inside of the refrigerator by a cooler 83 using the heat absorbed by the refrigerant F4. The heat pump device 70 may constitute, for example, a water heater or a washing machine with a drying function. The water heater uses the heat released from the refrigerant F4 to heat water with the heater 81. The washing machine with a drying function uses the heat released from the refrigerant F4 to heat air for drying clothes with the heater 81.

[0048] Next, a method for producing a fluorocarbon refrigerant, a method for storing the fluorocarbon refrigerant, and a method for producing a heat pump device in this embodiment will be described below. The operation of the carbon dioxide storage system 1 will also be described. In this embodiment, the method for producing a fluorocarbon refrigerant will be described using the carbon dioxide recovery unit 50 and the carbon recycling fluorocarbon refrigerant synthesis unit 60 described above. However, this is only one example, and the fluorocarbon refrigerant may be produced using other devices.

[0049] 2, by the operation of the blower 21, the gas to be treated is guided to the adsorption region 31 of the carbon dioxide adsorption unit 3 via the first supply path 2. In the adsorption region 31, the carbon dioxide contained in the gas to be treated is adsorbed by the adsorbent, and at least a portion of the carbon dioxide is removed from the gas to be treated. The gas to be treated, with its carbon dioxide concentration now reduced, is released from the adsorption region 31 into the atmosphere or the living space via the first outlet path 4.

[0050] When the adsorption of carbon dioxide by the adsorbent in the adsorption region 31 becomes impossible or difficult due to the adsorption of carbon dioxide, the adsorbent is exchanged between the adsorption region 31 and the regeneration region 32. The container that contains the adsorbent with carbon dioxide adsorbed therein in the adsorption region 31 is moved to the second region 3B of the carbon dioxide adsorption section 3, and the container that contains the regenerated adsorbent in the regeneration region 32 is moved to the first region 3A of the carbon dioxide adsorption section 3. As a result, the regenerated adsorbent is placed in the adsorption region 31, and the adsorbent with carbon dioxide adsorbed therein is placed in the regeneration region 32. By placing the regenerated adsorbent in the adsorption region 31, the adsorption region 31 becomes capable of adsorbing carbon dioxide again. By exchanging the adsorbent between the adsorption region 31 and the regeneration region 32 at regular intervals, the adsorbent capable of adsorbing carbon dioxide is maintained in the adsorption region 31.

[0051] The replacement of the adsorbent may be performed by removing the adsorbent in the adsorption region 31 from the container and moving it to the second region 3B, and by removing the adsorbent regenerated in the regeneration region 32 from the container and moving it to the first region 3A.

[0052] The adsorption region and the regeneration region can also be switched by changing the path. In Fig. 2, the first region 3A (the left part in Fig. 2) of the carbon dioxide adsorption unit 3 is the adsorption region 31. The first supply path 2 and the first outlet path 4 are connected to the first region 3A. The second region 3B (the right part in Fig. 2) is the regeneration region 32. The second supply path 6 and the second outlet path 9 are connected to the second region 3B.

[0053] By operating a valve provided in a branch path (not shown) or the like, the first supply path 2 and the first outlet path 4 are connected to the second region 3B, and the second supply path 6 and the second outlet path 9 are connected to the first region 3A. By this operation, the first region 3A becomes a regeneration region, and the second region 3B becomes an adsorption region. In this manner, the adsorption region and the regeneration region may be switched. After the second region 3B becomes an adsorption region, when carbon dioxide adsorption is performed for a certain period of time, the first region 3A is returned to the adsorption region and the second region 3B is returned to the regeneration region by operating a valve or the like. This is then repeated.

[0054] The regenerating fluid supply unit 5 supplies the regenerating fluid F1, and the regenerating fluid F1 is introduced into the regenerating region 32 of the carbon dioxide adsorption unit 3 via the second supply path 6, the heater 7, and the pressure reducer 8. The heater 7 heats the regenerating fluid F1 to a temperature suitable for desorption of carbon dioxide from the adsorbent in the regenerating region 32. The heater 7 heats the regenerating fluid F1 so that the temperature of the regenerating fluid F1 in the regenerating region 32 is 90°C to 120°C, for example. The pressure reducer 8 reduces the pressure of the regenerating fluid F1 to a pressure suitable for desorption of carbon dioxide from the adsorbent in the regenerating region 32.

[0055] In the regeneration region 32, carbon dioxide is desorbed from the adsorbent in the presence of regenerating fluid F1. The adsorbent is regenerated by the desorption of carbon dioxide. That is, the adsorbent that adsorbed carbon dioxide in the adsorption region 31 is regenerated in the regeneration region 32. The carbon dioxide desorbed from the adsorbent is contained in the regenerating fluid F1, and the regenerating fluid F1 containing carbon dioxide is discharged from the regeneration region 32 via the second outlet path 9 as a regeneration discharge fluid F2.

[0056] The regeneration discharge fluid F2 discharged from the regeneration region 32 is introduced into the carbon dioxide separator 10 via the second outlet path 9, through the compressor 11 and the cooler 12. The compressor 11 increases the pressure of the regeneration discharge fluid F2 to a pressure suitable for separation of carbon dioxide from the regeneration discharge fluid F2 in the carbon dioxide separator 10. The cooler 12 reduces the temperature of the regeneration discharge fluid F2, which has been increased to a high temperature by pressurization by the compressor 11, to a temperature suitable for separation of carbon dioxide from the regeneration discharge fluid F2 in the carbon dioxide separator 10.

[0057] The carbon dioxide separator 10 separates and captures at least a portion of the carbon dioxide contained in the regeneration discharge fluid F2 using a separation method such as liquefaction separation, membrane separation, or adsorption separation. The captured carbon dioxide is supplied to a hydrocarbon synthesis section 15 of the carbon recycle fluorocarbon refrigerant synthesis unit 60. That is, the carbon dioxide is captured from the gas to be treated by the carbon dioxide separator 10 of the carbon dioxide capture unit 50. The regeneration discharge fluid F2, in which the carbon dioxide concentration has been reduced by the separation of the carbon dioxide, is discharged from the carbon dioxide separator 10 as a discharge fluid F3.

[0058] As shown in Fig. 3, carbon dioxide captured in the carbon dioxide capture unit 50 is supplied to a hydrocarbon synthesis unit 15 of a carbon recycle fluorocarbon refrigerant synthesis unit 60. In the hydrocarbon synthesis unit 15, a hydrocarbon (methane) is synthesized from the carbon dioxide captured in the carbon dioxide capture unit 50 and hydrogen. The synthesized hydrocarbon is supplied to a dichloromethane synthesis unit 16.

[0059] In the dichloromethane synthesis section 16, dichloromethane is synthesized by a radical reaction between the hydrocarbons synthesized in the hydrocarbon synthesis section 15 and chlorine. The synthesized dichloromethane is supplied to the fluorocarbon refrigerant synthesis section 17.

[0060] In the fluorocarbon refrigerant synthesis section 17, the dichloromethane synthesized in the dichloromethane synthesis section 16 is reacted with hydrogen fluoride to synthesize difluoromethane, a fluorocarbon refrigerant. That is, the fluorocarbon refrigerant is synthesized using the carbon dioxide recovered from the gas to be treated, completing the method for producing a fluorocarbon refrigerant in this embodiment. The fluorocarbon refrigerant synthesized in the carbon recycle fluorocarbon refrigerant synthesis device 60 is supplied to the heat pump device 70 directly or via a cylinder or the like.

[0061] As shown in Fig. 4, the fluorocarbon refrigerant synthesized in the carbon recycling fluorocarbon refrigerant synthesis device 60 is filled as refrigerant F4 into the circulation path 85 of the heat pump device 70. As a result, the fluorocarbon refrigerant synthesized using carbon dioxide recovered from the gas to be treated as a raw material is filled and stored in the heat pump device 70. That is, the method for storing fluorocarbon refrigerant in this embodiment is completed. In manufacturing the heat pump device 70, the fluorocarbon refrigerant synthesized using carbon dioxide recovered from the gas to be treated as a raw material is filled into the heat pump device 70 that is not filled with refrigerant, thereby manufacturing the heat pump device 70. That is, the manufacturing method of the heat pump device in this embodiment is completed. Furthermore, by filling the heat pump device 70 with the fluorocarbon refrigerant, it becomes possible to start using the heat pump device 70.

[0062] When the heat pump device 70 reaches the end of its service life and is to be disposed of, the refrigerant F4 filled in the circulation path 85 is recovered. The refrigerant F4 is recovered from the circulation path 85 via a recovery port 86. As shown in Fig. 1, the refrigerant F4 recovered from the circulation path 85 of the heat pump device 70 may be supplied to the mixed refrigerant production section of the carbon recycled fluorocarbon refrigerant synthesis device 60 in order to produce a new refrigerant (or a mixed refrigerant).

[0063] The method for producing a fluorocarbon refrigerant in this embodiment includes a step of recovering carbon dioxide using an adsorbent, and a step of synthesizing a fluorocarbon refrigerant using the recovered carbon dioxide as a raw material. Therefore, the adsorbent can be used to capture carbon dioxide from the gas to be treated, such as the atmosphere, indoor air, or factory exhaust, and the captured carbon dioxide can be used as a raw material to synthesize a fluorocarbon refrigerant. The fluorocarbon refrigerant is chemically stable, and by using it as a heat medium in a heat pump device, for example, the synthesized fluorocarbon refrigerant can be stably stored in the heat pump device for the period from the manufacture of the heat pump device to its disposal (for example, 10 to 20 years). In other words, there is no need to prepare separate underground facilities or tanks for storing the captured carbon dioxide, and therefore the labor and energy required for storing and managing the captured carbon dioxide can be reduced.

[0064] In the method for producing a fluorocarbon refrigerant in this embodiment, in the step of recovering carbon dioxide, the carbon dioxide is recovered using renewable energy. If fossil fuels or the like are used to capture carbon dioxide from the gas to be treated, the capture operation generates greenhouse gases such as carbon dioxide, which is undesirable from the perspective of preventing global warming, for example. By capturing carbon dioxide using renewable energy, it is possible to suppress the generation of greenhouse gases during the capture operation.

[0065] In the fluorocarbon refrigerant production method of this embodiment, the step of synthesizing the fluorocarbon refrigerant includes synthesizing a hydrocarbon from the recovered carbon dioxide and hydrogen, synthesizing dichloromethane by a radical reaction between the hydrocarbon and chlorine, and synthesizing difluoromethane by reacting the dichloromethane with hydrogen fluoride. In this case, difluoromethane (CH2F2, refrigerant number: R32) does not contain chlorine as a component and has an ozone depletion potential (ODP) of 0, so that it can provide a preferable refrigerant from the viewpoint of protecting the ozone layer.

[0066] In the method for producing a fluorocarbon refrigerant in this embodiment, the hydrocarbon is methane. For example, it is possible to synthesize fluorocarbon refrigerants from hydrocarbons such as methane, ethane, propane, and butane, but among these hydrocarbons, methane has the simplest structure. Therefore, in the process of synthesizing hydrocarbons from recovered carbon dioxide, methane can be synthesized with relatively little energy, thereby reducing the energy required for synthesis.

[0067] In the method for producing a fluorocarbon refrigerant in this embodiment, a mixed refrigerant containing the difluoromethane as one of its components is produced. When disposing of an existing heat pump device, it is necessary to dispose of the fluorocarbon refrigerant filled in the heat pump device. In this case, for example, by producing a mixed refrigerant from difluoromethane produced by the fluorocarbon refrigerant production method of the present embodiment and a fluorocarbon refrigerant recovered from an existing heat pump device, it is possible to reduce the labor and cost required for disposing of the fluorocarbon refrigerant in the existing heat pump device.

[0068] In the method for producing a fluorocarbon refrigerant in this embodiment, the mixed refrigerant is a mixed refrigerant of the difluoromethane and an olefin-based refrigerant. The global warming potential (GWP) of olefin-based refrigerants (HFOs) is generally lower than that of hydrofluorocarbons (HFCs) such as difluoromethane. Therefore, by producing a mixed refrigerant from difluoromethane produced by the fluorocarbon refrigerant production method of this embodiment and an olefin-based refrigerant, a mixed refrigerant with a low global warming potential can be provided.

[0069] In the method for producing a fluorocarbon refrigerant in this embodiment, the mixed refrigerant is a mixed refrigerant of difluoromethane and chlorodifluoromethane. When disposing of an existing heat pump device, the fluorocarbon refrigerant filled in the heat pump device must also be disposed of. In addition, existing heat pump devices may use hydrochlorofluorocarbons (HCFCs), such as chlorodifluoromethane (CHClF2, refrigerant number: R22). In this case, for example, by producing a mixed refrigerant from difluoromethane produced by the fluorocarbon refrigerant production method of this embodiment and chlorodifluoromethane recovered from the existing heat pump device, it is possible to reduce the labor and cost required for disposing of chlorodifluoromethane in the existing heat pump device.

[0070] In the method for storing a fluorocarbon refrigerant in this embodiment, the fluorocarbon refrigerant synthesized by the above-mentioned method for producing a fluorocarbon refrigerant is filled into a heat pump device and stored therein. Therefore, by using the fluorocarbon refrigerant synthesized using the recovered carbon dioxide as a raw material as a heat medium in the heat pump device, the carbon dioxide can be stably stored in the heat pump device for the period from the manufacture to the disposal of the heat pump device (for example, 10 to 20 years). In other words, since there is no need to prepare separate underground facilities or tanks for storing the recovered carbon dioxide, the labor and energy required for storing and managing the recovered carbon dioxide can be reduced.

[0071] In the method for storing a fluorocarbon refrigerant in this embodiment, a heat pump device is manufactured by filling the heat pump device with the fluorocarbon refrigerant synthesized by the method for manufacturing a fluorocarbon refrigerant. Therefore, by using the fluorocarbon refrigerant synthesized using the recovered carbon dioxide as a raw material as a heat medium in the heat pump device, the carbon dioxide can be stably stored in the heat pump device for the period from the manufacture to the disposal of the heat pump device (for example, 10 to 20 years). In other words, since there is no need to separately prepare underground facilities or tanks for storing the recovered carbon dioxide, it is possible to provide a heat pump device that can reduce the labor and energy required for storing and managing the recovered carbon dioxide.

[0072] The carbon dioxide storage system 1 in this embodiment comprises a carbon dioxide capture device 50 that captures carbon dioxide using an adsorbent, a carbon recycle fluorocarbon refrigerant synthesis device 60 that synthesizes a fluorocarbon refrigerant using the captured carbon dioxide as a raw material, and a heat pump device 70 in which the fluorocarbon refrigerant is filled and stored. Therefore, the adsorbent can be used to capture carbon dioxide from a gas to be treated, such as the atmosphere, indoor air, or factory exhaust, synthesize a fluorocarbon refrigerant using the captured carbon dioxide as a raw material, and store the synthesized fluorocarbon refrigerant in the heat pump device 70. The fluorocarbon refrigerant is chemically stable, and by using it as a heat medium in the heat pump device 70, the synthesized fluorocarbon refrigerant can be stably stored in the heat pump device 70 for a period from the manufacture of the heat pump device 70 to its disposal (for example, 10 to 20 years). In other words, since there is no need to separately prepare underground facilities or tanks for storing the captured carbon dioxide, it is possible to provide a carbon dioxide storage system 1 that can reduce the labor and energy required for storing and managing the captured carbon dioxide.

[0073] In the carbon dioxide storage system 1 in this embodiment, the carbon dioxide capture device 50 captures carbon dioxide using renewable energy. If fossil fuels or the like are used to capture carbon dioxide from the gas to be treated, the capture operation generates greenhouse gases such as carbon dioxide, which is undesirable from the perspective of preventing global warming, for example. By using renewable energy to capture carbon dioxide, the carbon dioxide capture device 50 can suppress the generation of greenhouse gases during the capture operation.

[0074] In the carbon dioxide storage system 1 of this embodiment, the carbon recycle fluorocarbon refrigerant synthesis device 60 synthesizes hydrocarbons from the recovered carbon dioxide and hydrogen, synthesizes dichloromethane by a radical reaction between the hydrocarbon and chlorine, and synthesizes difluoromethane by reacting the dichloromethane with hydrogen fluoride. In this case, difluoromethane (CH2F2, refrigerant number: R32) does not contain chlorine as a component and has an ozone depletion potential (ODP) of 0, so a carbon dioxide storage system 1 can be provided that uses a refrigerant that is preferable from the perspective of protecting the ozone layer.

[0075] In the carbon dioxide storage system 1 of this embodiment, the hydrocarbon is methane. For example, it is possible to synthesize fluorocarbon refrigerants from hydrocarbons such as methane, ethane, propane, and butane, and among these hydrocarbons, methane has the simplest structure. Therefore, in the process of synthesizing hydrocarbons from recovered carbon dioxide, the hydrocarbon synthesis section 15 of the carbon recycling fluorocarbon refrigerant synthesis unit 60 can synthesize methane with relatively little energy, thereby reducing the energy required for synthesis.

[0076] In the carbon dioxide storage system 1 of this embodiment, the refrigerant filled in the heat pump device 70 is a mixed refrigerant that contains the difluoromethane as one of its components. When disposing of an existing heat pump device, it is necessary to dispose of the fluorocarbon refrigerant filled in the heat pump device. In this case, for example, a mixed refrigerant is produced from difluoromethane produced by the carbon recycling fluorocarbon refrigerant synthesis device 60 and the fluorocarbon refrigerant recovered from the existing heat pump device, and this mixed refrigerant is filled and used in the heat pump device 70, thereby reducing the labor and cost required for disposing of the fluorocarbon refrigerant in the existing heat pump device.

[0077] In the carbon dioxide storage system 1 of the present embodiment, the mixed refrigerant is a mixed refrigerant of the difluoromethane and an olefin-based refrigerant. The global warming potential (GWP) of olefin-based refrigerants (HFO) is generally lower than that of hydrofluorocarbons (HFC) such as difluoromethane. Therefore, by producing a mixed refrigerant from difluoromethane produced by the carbon recycling fluorocarbon refrigerant synthesis unit 60 and an olefin-based refrigerant and filling the heat pump unit 70 with this mixed refrigerant, it is possible to provide a carbon dioxide storage system 1 that uses a mixed refrigerant with a low global warming potential.

[0078] In the carbon dioxide storage system 1 of the present embodiment, the mixed refrigerant is a mixed refrigerant of difluoromethane and chlorodifluoromethane. When disposing of an existing heat pump device, the fluorocarbon refrigerant filled in the heat pump device must also be disposed of. In addition, in some existing heat pump devices, hydrochlorofluorocarbons (HCFCs), such as chlorodifluoromethane (CHClF2, refrigerant number: R22), are used. In this case, for example, a mixed refrigerant is produced from difluoromethane produced by the carbon recycling fluorocarbon refrigerant synthesis device 60 and chlorodifluoromethane recovered from the existing heat pump device, and this mixed refrigerant is filled and used in the heat pump device 70, thereby providing a carbon dioxide storage system 1 that can reduce the labor and cost required for disposing of chlorodifluoromethane in the existing heat pump device.

[0079] In the carbon dioxide storage system 1 of the present embodiment, the heat pump device 70 includes a recovery port 86 that recovers the fluorocarbon refrigerant filled in the heat pump device 70. In this case, when the heat pump device 70 reaches the end of its service life and is to be disposed of, the filled fluorocarbon refrigerant can be recovered via the recovery port 86. This allows the fluorocarbon refrigerant to be properly recovered, and also reduces the effort required for recovering the fluorocarbon refrigerant.

[0080] The technical scope of the present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present disclosure. For example, one or more concentrators (carbon dioxide concentrators) may be provided in the second outlet path 9. The concentrators increase the concentration of carbon dioxide in the regeneration discharge fluid F2 by, for example, liquefaction separation, membrane separation, adsorption separation, or other techniques. This can improve the energy efficiency in the carbon dioxide separator 10. The concentrators may be provided in the first supply path 2. In addition, the concentrators may be provided between the carbon dioxide capture device 50 and the carbon recycled fluorocarbon refrigerant synthesis device 60.

[0081] In the above embodiment, the pressure reducer 8 is provided downstream of the heater 7, but this is not limiting, and the pressure reducer 8 may be provided upstream of the heater 7 depending on the system specifications.

[0082] As a heat exchanger such as a heater or a cooler, a known heat exchanger can be used, such as a multi-tube heat exchanger, a plate heat exchanger, a coil heat exchanger, a double-tube heat exchanger, a spiral heat exchanger, etc.

[0083] In the above embodiment, the atmosphere, indoor air, and factory exhaust gas are exemplified as the gas to be treated, but nitrogen gas, hydrogen gas, oxygen gas, methane, etc. containing carbon dioxide may also be used as the gas to be treated.

[0084] In the above embodiment, a hydrocarbon is synthesized from the recovered carbon dioxide and hydrogen, the hydrocarbon is reacted with chlorine in a radical reaction to synthesize dichloromethane, and the dichloromethane is reacted with hydrogen fluoride to synthesize difluoromethane, but the synthesis method is not limited to this. A fluorocarbon refrigerant such as difluoromethane may be synthesized from the recovered carbon dioxide by using another method.

[0085] The catalysts in the hydrocarbon synthesis section 15, the dichloromethane synthesis section 16, and the fluorocarbon refrigerant synthesis section 17 are not limited to those shown in the above embodiment, and may be changed to other appropriate catalysts depending on the system specifications.

[0086] In the above embodiment, difluoromethane is synthesized, but the present invention is not limited to this, and hydrofluorocarbons other than difluoromethane may be synthesized. [Explanation of symbols]

[0087] 1 Carbon Dioxide Storage System 2. First supply route 3 Carbon dioxide adsorption section 3A 1st area 3B 2nd area 4. First derivation path 5 Regeneration fluid supply section 6 Second Supply Route 7 Heater 8 Pressure reducer 9 Second derivation route 10 Carbon dioxide separator 11 Compressor 12 Cooler 15 Hydrocarbon Synthesis Department 16 Dichloromethane synthesis section 17 Fluorocarbon refrigerant synthesis section 21 Blois 31 Adsorption area 32 Play area 50 Carbon dioxide capture equipment 60 Carbon recycling fluorocarbon refrigerant synthesis equipment 70 Heat pump equipment 80 Heat Pump 81 Heater 82 Expander 83 Cooler 84 Compressor 85 Circulation Route 86 Collection Port F1 regeneration fluid F2 Regeneration exhaust fluid F3 Discharge fluid F4 refrigerant F5 Fluid F6 Fluid

Claims

1. capturing carbon dioxide using an adsorbent; and synthesizing a fluorocarbon refrigerant using the recovered carbon dioxide as a raw material. How fluorocarbon refrigerants are manufactured.

2. In the step of recovering carbon dioxide, carbon dioxide is recovered using renewable energy. The method for producing the fluorocarbon refrigerant according to claim 1.

3. In the step of synthesizing the fluorocarbon refrigerant, a hydrocarbon is synthesized from the recovered carbon dioxide and hydrogen, dichloromethane is synthesized by a radical reaction between the hydrocarbon and chlorine, and difluoromethane is synthesized by a reaction between the dichloromethane and hydrogen fluoride. The method for producing the fluorocarbon refrigerant according to claim 1.

4. The hydrocarbon is methane. The method for producing a fluorocarbon refrigerant according to claim 3.

5. producing a mixed refrigerant containing the difluoromethane as one of its components; The method for producing a fluorocarbon refrigerant according to claim 3.

6. The mixed refrigerant is a mixed refrigerant of the difluoromethane and an olefin-based refrigerant. The method for producing a fluorocarbon refrigerant according to claim 5.

7. The mixed refrigerant is a mixed refrigerant of difluoromethane and chlorodifluoromethane. The method for producing a fluorocarbon refrigerant according to claim 5.

8. The fluorocarbon refrigerant synthesized by the method for producing a fluorocarbon refrigerant according to any one of claims 1 to 7 is filled into a heat pump device and stored. How to store fluorocarbon refrigerants.

9. A heat pump device is manufactured by filling a heat pump device with the fluorocarbon refrigerant synthesized by the method for producing a fluorocarbon refrigerant according to any one of claims 1 to 7. A method for manufacturing a heat pump device.

10. a carbon dioxide capture device that captures carbon dioxide using an adsorbent; a carbon recycling fluorocarbon refrigerant synthesis device that synthesizes fluorocarbon refrigerants using the recovered carbon dioxide as a raw material; A heat pump device in which the fluorocarbon refrigerant is filled and stored. Carbon dioxide storage systems.

11. The carbon dioxide capture device captures carbon dioxide using renewable energy.

11. The carbon dioxide storage system of claim 10.

12. The carbon recycling fluorocarbon refrigerant synthesis device synthesizes hydrocarbons from the recovered carbon dioxide and hydrogen, synthesizes dichloromethane by a radical reaction between the hydrocarbons and chlorine, and synthesizes difluoromethane by a reaction between the dichloromethane and hydrogen fluoride.

11. The carbon dioxide storage system of claim 10.

13. The hydrocarbon is methane.

13. The carbon dioxide storage system of claim 12.

14. The refrigerant filled in the heat pump device is a mixed refrigerant containing the difluoromethane as one of its components.

13. The carbon dioxide storage system of claim 12.

15. The mixed refrigerant is a mixed refrigerant of the difluoromethane and an olefin-based refrigerant.

15. The carbon dioxide storage system of claim 14.

16. The mixed refrigerant is a mixed refrigerant of difluoromethane and chlorodifluoromethane.

15. The carbon dioxide storage system of claim 14.

17. The heat pump device includes a recovery port for recovering the fluorocarbon refrigerant filled in the heat pump device.

17. The carbon dioxide storage system of any one of claims 10 to 16.

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